The relationship between insulin resistance and the intake of dairy products : a cross-sectional study among employees at a private university in Lebanon

Abstract

Background: Worldwide, the prevalence of insulin resistance ranges from 15.5% to 46.5%, among adults. Lebanon reported one of the highest rates reaching 44.6%. The literature is suggesting an association between dairy product consumption and insulin resistance, however results are still inconclusive. To our knowledge, no study has examined this association in the Middle Eastern Region. Objectives: Examine the association between dairy products' consumption and insulin resistance in a sample of Lebanese adults and to assess the effect of different types of dairy products on insulin resistance. Materials & Methods: This is a cross-sectional study conducted among NDU employees, in Zouk Mosbeh, North and Shouf campuses. Four questionnaires were administered including a background and IPAQ (International Physical Activity Questionnaire) short form questionnaires, food frequency questionnaire and a 24h recall. Bioelectric Impedance Analysis (BIA) was used to measure percent body fat (PBF). Fasting insulin levels were measured using Enzyme Linked Immunosorbent Assay (ELISA) technique. Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was used to quantify insulin resistance. A person with HOMA-IR? 2.5 was considered as insulin resistant. Statistical analyses were performed using the Statistical Package for Social Sciences (SPSS) version 23 for Windows. P< 0.05 was considered to be statistically significant. Results: The sample consisted of 286 subjects (46.9 % men and 53.1 % women) with a mean age of 41.2±11.0 years. Average dairy product intake in the total sample was 2.2 servings per day with no significant difference between genders (p=0.999). More than one third of participants (3 8.0%) were insulin resistant with higher proportion of men (47.0%) being insulin resistant compared to women (31.6%) (p=0.008). After controlling for confounders, variables that were directly associated with HOMA-IR when total dairy intake was included in the model were gender (p=0.037), marital status (p=0.01 1), income (p=0.038), PBF (p<O.00l) and fiber (p=0.035) while inversely associated factors included carbohydrates only (p=0.039). The same factors were associated with HOMA-IR, except carbohydrates, when the types of dairy products were included in the model, in addition to yogurt intake (p0.013). Conclusion: This study suggests that yogurt consumption, but not total dairy consumption, was associated with increased insulin resistance.